docs: def unit_conversion(thing, units, length=False):
      """converts base data between metric, imperial, or nautical units"""
      if 'n/a' == thing:
          return 'n/a'
      try:
          thing = round(thing * CONVERSION[units][0 + length], 2)
      except TypeError:
          thing = 'fubar'
      return thing, CONVERSION[units][2 + length]